Optical Receiver Frequency-Domain Equalization to Reduce Power
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Solution Overview
Problem
High power consumption and excessive resource occupation due to the large number of taps required for time domain equalization in optical communication systems, particularly in next-generation systems like 800G, which is not feasible for current 400G systems.
Innovation Solution
Implement frequency domain equalization by combining any two channels of digital electrical signals into a complex signal for processing, using Fourier transforms and tap coefficient adjustments to reduce the number of equalizers and resources needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If time domain equalization with a large number of taps is used to compensate for severe bandwidth limitation, then signal quality is improved, but power consumption and resource occupation increase excessively
Solution Approach 1:
The patent combines two real-valued channels into a single complex-valued channel for joint frequency domain equalization. By merging the processing of multiple channels into one complex signal, the number of required equalizers is reduced, thereby decreasing power consumption and computational resources while maintaining signal quality through unified equalization processing.
Solution Approach 2:
The patent transforms the equalization process from time domain to frequency domain by applying Fourier transform. This parameter change in the processing domain allows the use of frequency domain equalization instead of time domain equalization, reducing the computational complexity and resource requirements while achieving effective ISI compensation.
2Reliability
If time domain equalization with a large number of taps is used to compensate for severe bandwidth limitation, then signal quality is improved, but device complexity increases
Solution Approach 1:
The patent combines two real-valued channels into a single complex-valued channel for joint frequency domain equalization. By merging the processing of multiple channels into one complex signal, the number of required equalizers is reduced, thereby decreasing power consumption and computational resources while maintaining signal quality through unified equalization processing.
Solution Approach 2:
The patent transforms the equalization process from time domain to frequency domain by applying Fourier transform. This parameter change in the processing domain allows the use of frequency domain equalization instead of time domain equalization, reducing the computational complexity and resource requirements while achieving effective ISI compensation.
3Reliability
If four independent time domain equalizers are used for multi-channel transmission, then each channel signal quality is improved, but total power consumption and resource occupation become unacceptably high
Solution Approach 1:
The patent combines two real-valued channels into a single complex-valued channel for joint frequency domain equalization. By merging the processing of multiple channels into one complex signal, the number of required equalizers is reduced from four independent TDEQs to fewer FDEQs, thereby decreasing power consumption and computational resources while maintaining signal quality through unified equalization processing.
Solution Approach 2:
The patent makes a single complex-valued equalizer handle multiple channels simultaneously through frequency domain processing. The unified equalizer processes both in-phase and quadrature components, enabling one equalizer to perform the function of multiple independent equalizers, thus reducing the total quantity of equalizers required in the system.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Reduces power consumption and system complexity while maintaining effective signal quality compensation for inter-symbol interference, achieving comparable performance to time domain equalization with fewer resources.
Implementation Method 1
The optical receiver converts the first complex signal into a frequency domain signal in a manner such as Fourier transform
Implementation Method 2
The optical receiver converts the second complex signal into a time domain signal in a manner such as inverse Fourier transform
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Embodiments of the present invention provide a frequency domain equalization method, an equalizer, an optical receiver, and a system. The frequency domain equalization method includes: An optical receiver obtains a first complex signal. The first complex signal is a time domain signal. The first complex signal is obtained based on two channels of mutually independent digital electrical signals. The optical receiver converts the first complex signal into a frequency domain signal, and multiplies the first complex signal in frequency domain by a tap coefficient to obtain a second complex signal. The tap coefficient is used to implement signal compensation for the first complex signal in frequency domain. The optical receiver converts the second complex signal into a time domain signal, divides the second complex signal in time domain into two channels of real signals, and outputs the two channels of the real signals. Two channels of digital electrical signals are combined into one channel of a complex signal to implement frequency domain equalization, to reduce power consumption and occupied resources caused due to an excessively large quantity of taps in time domain equalization and reduce system complexity.